By way of background, covers for bolt and screw connectors have been used in the art for providing an ornamental and/or protective covering for the protruding end of the connector. In carpentry, for example, the bolt can be covered with a decorative cover to hide the presence of the fastener. Sometimes, a well is made for the bolt head and a cover is inserted into the opening.
Alternatively, the cover can comprise spring loaded clips which are snapped into the opening over the bolt. Thus the bolt can be placed out-of-sight for ornamental purposes. Such covers are commonly seen in the manufacture of store fixtures and furniture made of metal and plastic.
Ornamental covers for bolts have a long standing use in the plumbing of toilets, wherein a porcelain cover is used to hide from sight the bolt used to connect the bowl to the floor. See for example, U.S. Pat. No. 2,020,522 to Seguin and U.S. Pat. No. 3,881,391 to Dereszynski.
In Seguin, the cover is attached to a washer by a threaded means. The washer is notched around the periphery to facilitate removal after a long period of time. Thus, the washer includes a groove for inserting a gasket to prevent water from passing through the notches and rusting the bolt. Alternatively, the gasket can be placed over the top side of the notched washer and held in place by a spring loaded flange inside the cap. In the '391 patent, the cover is provided a mounting disc inserted inside. The mounting disk can be screwed to the protruding end of bolt used to fasten the bowl to the floor. However, the cover for the toilet bowl fastening bolt has generally been attached using putty or adhesive.
It has often been desirable to cover the end of a projecting bolt for protective purposes, both to prevent rusting and/or marring of the bolt threads and as a safety precaution. U.S. Pat. No. 2,538,483 to Summers, U.S. Pat. No. 1,254,514 to Lehmann, and U.S. Pat. No. 1,506,005 to Kraft, U.S. Design Pat. No. Des. 311,131 disclose protective covers with internal threads for threadedly receiving the end of a projecting bolt. Similarly, U.S. Pat. No. 4,784,555 to Cantrell has an internal gasket for mounting a nut by means of friction.
Heretofore, threaded caps have not been used to seal bolt and screw connectors. In addition, seal caps have not previously been attached to washers made from all-thread bolt stock.